Lead-free compatibility in wavesoldering ovens

Vitronics Soltec wavesoldering machines are designed to deliver optimum results with lead-free alloys and fluxes. Lead-free soldering differs principally from lead-bearing processes in the higher temperatures needed. New fluxes are required with activators designed to meet these requirements. The fluxing units can be used with an alcohol solvent, but also apply VOC-free, water-based flux. The nozzles reduce the droplet size, which is required for fluxes with water as a solvent to getthe best interaction. Increased atomization transfers the flux to the topside of the holes, which is needed for good hole filling with solder. The preheating delivers highly efficient heat transfer for uniform temperature distribution, increase of topside board temperature, and evaporation of the waterin the flux. Corrosion-resist-ant coated impellers have de-monstrated compatibility with lead-free alloys. Titanium bolts are used in the solderpot area to prevent damage. Longer contact times can be achieved with a number of available wave formers. Updated software exercise controls to avoid tin explosions and impeller damage. The patented SmartWave forces the solder to flow into the top of the through-holes, delivering good filled joints even with alloys that have marginal solderability, such as SnCu.

EPP 174